Pressure intensifier

ABSTRACT

A pressure intensified including a base body ( 1 ), a cover ( 2 ) for closing the base body ( 1 ), a bottle ( 4 ) located in an interior of the base body ( 1 ) and filled with a liquid internal gas ( 5 ), a valve ( 3 ) extending through the cover ( 2 ) and connected with the bottle ( 4 ), and an external gas ( 6 ) filling an intermediate space between the bottle ( 4 ) and the base body ( 1 ) and having a gaseous component and a liquid component that substantially corresponds to the inner gas ( 5 ).

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a pressure intensifier including a base body, a cover for closing the base body, a bottle located in an interior of the base body and filled with a liquid internal gas, a valve extending through the cover and connected with the bottle, and an external gas filling an intermediate space between the bottle and the base body.

[0003] 2. Description of the Prior Art

[0004] In gas-driven setting tools, the drive energy is produced by combustion of a gas-air mixture in a combustion chamber of a setting tool. The drive energy acts on a piston which transmits the drive energy to a fastening element being driven into a constructional component.

[0005] For producing a gas-air mixture, a internal gas, which is stored in a pressure intensifier, is used. A metering head, which is connected with the pressure intensifier, upon being actuated, injects a predetermined amount of the internal gas, which is stored in the pressure intensifier, into the combustion chamber of the setting tool. The internal gas is injected in a liquid form. In order to be able to meter an exact amount of the internal gas by volume, the liquid internal gas is stored in the pressure intensifier with use of a two-chamber system.

[0006] The first chamber of the two-chamber system is formed by an inner space of a bottle located in the interior of the base body of the pressure intensifier. The internal liquid gas is stored in the bottle. The second chamber is formed by the intermediate space between the bottle and the base body and is filled with an external gas.

[0007] In order to insure that the bottle is always compressed during the operation and that the internal gas is metered in a liquid form independent from the position of the pressure intensifier, as an external gas, a gas, which has a greater vapor pressure than the internal gas, is used.

[0008] The drawback of using different gases with different vapor pressures consists in that because of different concentrations of the gases in the intermediate space and in the bottle, the internal and external gases migrate through the bottle wall and, after a certain time, on one hand, they become mixed and, on the other hand, a pressure balance is established between the two chambers, the intermediate space and the bottle.

[0009] The object of the present invention is to provide a two-chamber pressure intensifier which would insure delivery of the internal gas without any disturbances.

SUMMARY OF THE INVENTION

[0010] This and other objects of the present invention, which will become apparent hereinafter, are achieved by providing an external gas having gaseous and liquid components, with the liquid component substantially corresponding to the internal gas.

[0011] The use of substantially identical gases as an internal gas and a liquid component of the external gas insures that the quality of the internal gas is not affected by the migration or diffusion of the external gas, and no disturbance occurs when the internal gas is delivered through the valve out of the pressure intensifier.

[0012] Preferably, the inner gas is selected form a group including propane, n-butane, propine, propene, propadien, dimethyletil, isobutelene, and the like.

[0013] Advantageously, the gaseous component of the external gas is selected from a group consisting of air, oxygen, argon, helium, carbon dioxide, nitrous oxide, and neon. The advantage of these gases consists in that they poorly diffuse through various material, in particular, hydrocarbon polymers. When the liquid component is enriched with one of these gases, the pressure difference, which is necessary for the pressure intensifier to function, is obtained.

[0014] In order to insure that the bottle is always compressed during operation so that its content, the internal gas, is always metered in a liquid form, preferably, the pressure in the intermediate space exceeds that in the bottle. The increased pressure in the intermediate space is insured by the gaseous component of the external gas.

[0015] The bottle is formed of a compound foil with an aluminum layer. The inner surface of the bottle is formed, e.g., of polyethylene or polypropylene, which insures internal bonding of the foil and welding of the bottle with the valve body. The valve body can be formed, e.g., of polyacetal or of the same material as the inner surface of the bottle. This insures a very good welding connection of the valve body with the bottle. When the valve body is mechanically connected with the bottle, the valve body is formed of gas permeable material, e.g., polymerethylene or polypropylene. In order to provide a rigid base body having at the same time a small weight, the base body is formed preferably of aluminum or tinned sheet metal.

[0016] The novel features of the present invention, which are considered as characteristic for the invention, are set forth in the appended claims. The invention itself, however, both as to the construction and its mode of operation, together with additional advantages and objects thereof, will be best understood from the following detailed description of preferred embodiments, when read with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In the Drawings: Single FIGURE shows a cross-sectional view of a pressure intensifier according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0018] A pressure intensifier according to the present invention, which is shown in the drawings, has a substantially cylindrical base body 1 provided with a bottom 7 days in its lower end region. The base body 1 has its opposite, upper end region closed with a cover 2. A valve 3 extends through the cover 2. The valve body 8, which extends into the interior of the base body 1 is connected with a compressible bottle 4 located inside the base body 1. A liquid internal gas 5 such as, e.g., propane, n-butane, propine, propene, propadiene, dimethyletil, or isobutyelene-based fills the bottle 4.

[0019] The intermediate space between the base body 1 and the bottle 4 is filled with an external gas 6 which has liquid and gaseous components. The liquid component of the external gas 6 is a gas identical to the internal gas 5. The gaseous component of the external gas 6 is one of the following gases: air, oxygen, argon, helium, carbon dioxide, nitrous oxide, or neon.

[0020] The pressure of the gas in the intermediate space is greater than in the bottle 4.

[0021] The inner surface of the bottle 4 is formed, e.g., of polyethelene, polyacetal, or polypropylene. The valve body 8 of the valve 3 is formed of polyethylene or polypropylene, so that a good welding connection of the bottle 4 with the valve body 8 is formed. The base body 1 is formed of aluminum or tinned sheet metal.

[0022] Though the present invention was shown and described with references to the preferred embodiment, such are merely illustrative of the present invention and is not to be construed as a limitation thereof, and various modifications of the present invention will be apparent to those skilled in the art. It is, therefore not, intended that the present invention be limited to the disclosed embodiment or details thereof, and the present invention includes all variations and/or alternatives embodiments within the spirit and scope of the present invention as defined by the appended claims. 

What is claimed is:
 1. A pressure intensifier, comprising a base body (1); a cover (2) for closing the base body (1); a bottle (4) located in an interior of the base body (1); a valve (3) extending through the cover (2) and connected with the bottle (4); a liquid internal gas (5) filling the bottle (4); and an external gas (6) filling an intermediate space between the bottle (4) and the base body (1) and having a gaseous component and a liquid component that substantially corresponds to the inner gas (5).
 2. A pressure intensifier according to claim 1, wherein the inner gas (5) is selected from a group consisting of propane, n-butane, propine, propene, propadiene, dimethyletil, and isobutelene-based gas.
 3. A pressure intensifier according to claim 1, wherein the gaseous component of the external gas (6) is selected from a group consisting of air, oxygen, argon, helium, carbon dioxide, nitrous oxide, and neon.
 4. A pressure intensifier according to claim 1, wherein a pressure in the intermediate space exceeds a pressure in the bottle (4). 